Pasta, spaghetti, or other injection noodle products are generally produced by extrusion of noodle dough through a die.
Usually, pasta is preferably formed to have proper surface roughness so that pasta sauce can stick to the pasta in a better way.
When conventional die pieces for extrusion molded noodles are used, pasta obtained immediately after the start of production has proper surface roughness, but the surface roughness of the produced pasta increases or decreases over time, which can cause a problem in that the pasta can become difficult to automatically feed and weigh. Conventionally, therefore, die pieces for extrusion molded noodles are replaced by new ones a certain period of time (about 48 hours) after the start of production.
Concerning techniques about die pieces for extrusion molded noodles, for example, Patent Literature 1 discloses an extrusion die piece for use in production of noodles, which has a substantially circular extrusion hole having projections that are spaced by a certain distance and protrude in a staggered fashion toward each other from circumference parts opposed to each other in the radial direction, wherein the projection tips extend to positions beyond the center line of the extrusion hole, respectively.
Patent Literature 2 discloses a die piece for extrusion molded noodles having one or more extrusion holes whose cross-section is substantially rectangular, wherein the extrusion hole has a pair of opposed convex-arc short sides and a pair of opposed linear long sides, one of the long sides has a convex part, and the other of the long side has a concave part.
However, the techniques disclosed in Patent Literatures 1 and 2 are all for modifying the cross-sectional shape of pasta, and any of them are not for controlling the surface roughness of pasta (degree of pasta surface roughness).